Wax modifying agent



Patented Mar. 31, 1953 f WAX MODIFYING AGENT Eugene Lieber, Chicago,Ill., and Aloysius F. Cashman, Staten Island, N. Y., assignors toStandard Oil Development Company, a corporation of Delaware No Drawing.Application December 1, 1949, Serial No. 130,606

2 Claims. (Cl. 260-407) The present invention relates to the art ofproducing wax modifying agents particularly those which may be employedfor reducing the pour point or waxy lubricating oils or in connectionwith processes for dewaxing oils containing paramnic wax or in any otherprocess or composition in which a wax structure is to be modified byreducing the crystal size. The invention will be fully understood fromthe following description.

In U. S. Patent 2,251,550, granted to E. Lieber, there was described aprocess of producing an effective wax modifying agent by heatcondensation-polymerization of an acid chloride which had been derivedfrom fatty acids containing to 20 carbon atoms. The production of such amaterial required a step of converting the fatty acid into a fatty acidchloride prior to the heat treatment.

It has now been found, in accordance with the present invention, thatsatisfactory wax modifying agents may be prepared by the directpyrolysis of fatty acids and the like. For this purpose, aliphaticcarboxylic acids containing 10 to 30 carbon atoms per molecule, therange of 12 to 22 carbon atoms being more generally preferred, areheated at a temperature of 400 F. to 800 F., preferably 500 F. to 700F., for a period of 1 to 20 hours, more commonly from 4 to 10 hours.While normal atmospheric pressure may be used, reduced pressures areoften advantageous in carrying out this process. It is enerallyadvantageous to conduct the heat treatment in the presence of a heatconducting material of large surface area such as steel wool, althoughsuch material is not required. The resulting product may be refined invarious ways, such as by filtration or distillation to remove rawmaterials and low boiling condensation products, or by solventextraction, clay treating, etc.

The exact nature of the chemical process involved is not known, but itis believed that the process is primarily a dehydration-condensationreaction.

The aliphatic acids employed in the process of the present invention maybe straight or branched chain compounds, saturated or unsaturated, andmay be monobasic or polybasic. Examples of the more preferred acidsinclude stearic acid, palmitic acid, margaric acid, lauric acid, oleicacid, sebacic acid, coconut oil acids, wax oxidation acids, and thelike.

The hydrocarbon base stocks into which the wax modifying agents of thepresent invention are incorporated are preferably waxy mineral heated at600 F. for 6 hours.

lubricating oils such as a paraflinic lubricating oil base stock or amixed base, which may have been subjected to any one or more of thecommonly used refining steps, such as distillation, solvent extraction,acid treating, clay treating, etc., as Well as partial dewaxing. Suchoil base stock may either be one which is within the known lubricatingoil viscosity range or it may be an oil of much lower viscosity, such asa gas oil used in the preparation of hydraulic oils, etc., and which mayhave a viscosity as low as 40 seconds Saybolt at 100 F. Solidhydrocarbon base stocks maybe used, such as parafiin wax for hot meltcoating of paper.

In carrying out the invention it is desirable to use the wax modifyingadditive in proportions of about 0.1 to 5% based on the lubricating oilbase stock, although usually 1% is sufiicient for most purposes. It willbe understood that different oils require slightly different amounts ofthe material to produce a given drop in pour point. and likewisematerial prepared from different types of acids vary somewhat in theirpour depressing stren th.

The wax modifying agents of the present invention may be used inconnection with the process for dewaxin hydrocarbon oils and then addedeither to the oil to be dewaxed or to the oil after it has been dilutedwith naphtha or with other su table dewaxing solvents. The mixture ischilled to the wax separating point and the actual separation may beconducted either by filtration, sedimentation or centrifugation. In anycase it will be found that the presence of a relatively small amount ofthe material, say 1% more or less. will considerably increase the easewith which the separation is accomplished and increase the rate at whichchilling may be carried out.

The desirable results obtained by the use of the additives described inthe present specification may be illustrated by the following examplewhich, however, is not to be considered as limiting the scope of theinvention in any way.

Example 400 g. of commercial stearic acid and 10 g. of steel wool wereplaced in a Claisen flask and The product was recovered by vacuumdistillation to 600 F. under a pressure of mm. mercury. The steel woolwas removed from the product by filtering the bottoms from thedistillation step through a steam funnel. A yield of 247 g. of a darkwaxy material was obtained. The pour depressing potency of this productwas tested by blending 1% by weight of the same in a waxy base oilconsisting of 80 parts by weight of a. light parafiinic lubricating oilof the white Pennsylvania type and 20 parts of Pennsylvania, brightstock, the blend having-aviscosity of 5.0 secondssayboltat 210-F. Theunblended base stock exhibited a pourj point of +30 F. as determined bythe standard ASTM procedure while the blend containing 1% of theadditive exhibited a pour point under this procedure of -30 F.

This application is a continuationein-partbf Serial No. 789,576, filedDecember .3, .1947, for the same inventors which is nowabandoned.

What is claimed is:

1. A process for the formation of a material having the characteristicof lowering the pour point of waxy mineral oils which comprises heatingstearic acid at a temperature of from500".;F.

5 ing is about 6 hours.

EUGENE LIEBER. ALOYSIUS F. CASHIMAN.

REFERENCES CITED The following references are of record in the 'file'ofthis patent:

"UNITED STATES PATENTS Number Name Date 15 2,201,767 Franceway May 21,1940 2,256,353 Rheineck et a1. Sept. 16, 1941 2,349,165 Grant May 16,1944 2,373,015 Cowan et al. Apr. 3, 1945

1. A PROCESS FOR THE FORMATION OF A MATERIAL HAVING THE CHARACTERISTICOF LOWERING THE POUR POINT OF WAXY MINERAL OILS WHICH COMPRISES HEATINGSTEARIC ACID AT A TEMPERATURE OF FROM 500* F. TO 700* F. FOR A PERIOD OFFROM 4 TO 10 HOURS IN THE PRESENCE OF STEEL WOOL.